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Differences in Soil Microbial Biomass and Activity for Six Agroecosystems with a Management Disturbance Gradient

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Pedosphere 2004年第4期14卷 441-448页

作者： ZHANGWei-j.an FENGj.n-Xia j.WU K.parker DepartmentofAgronomy NanjingAgriculturalUniversityNanjing210095（China）. DepartmentofPlantPathology NorthCarolinaStateUniversityRaleighNC27695（USA）

Different management practices in six agroecosystems located near Goldsboro, NC, USA were conducted including a successional field (SU), a plantation woodlot (WO), an integrated cropping system with animals (IN), an organic farming system (OR), and two cash-grain cropping systems employing either tillage (CT) or no-tillage (NT) to examine if and how microbial biomass and activity differ in response to alterations in disturbance intensity from six land management strategies. Results showed that soil microbial biomass and activity differed, with microbial activity in intermediately disturbed ecosystems (NT, OR, IN) being significantly higher (P ＜ 0.01) than systems with either high or low disturbance intensities. There was also a significant and a highly significant ecosystem effect from the treatments on microbial biomass C (MBC) (P ＜ 0.05) and on microbial activity (respiration) (P ＜ 0.01), respectively. Multiple comparisons of mean respiration rates distinctly separated the six ecosystem types into three groups: CT ＜ NT, SU and WO ＜ OR and ***, for detecting microbial response to disturbance changes these results indicated that the active component of the soil microbial community was a better indicator than total biomass.

关键词： agroecosystems carbon retention disturbance intensity microbial biomass soil microbial activity

Reminiscing my sixty year pursuit of the physics of the Sun and the Galaxy

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Research in Astronomy and Astrophysics 2014年第1期14卷 1-14页

作者： Eugene N.parker Department of Physics Department of Astronomy and AstrophysicsUniversity of Chicago

Reminiscing begins with childhood and passes on to student days through graduate school and the first real contact with research. Then early academic posi- tions and stumbling efforts to pursue my ideas. The first significant progress came as a research associate with Prof. W. M. Elsasser at the University of Utah, beginning with an introduction to magnetohydrodynarnics and the generation of the geomagnetic field through induction in the liquid metal core of Earth. A move to the University of Chicago to work with Prof. j. A. Simpson, on the implications of cosmic ray varia- tions and interplanetary magnetic fields, led to the theory of coronal expansion and the solar wind and then to exploring the dynamical effects of cosmic rays on the galactic magnetic field. Spontaneous current sheets and intrinsic rapid reconnection in interlaced magnetic field line topologies were the next big proj.ct, leading up to retirement. Finally, it is a pleasure to recall my many associates, whose fresh thinking helped stimulate the daily research activities.

关键词： dynamo -- magnetohydrodynamics -- plasma

Lumped Parameter Outflow Models for 1-D Blood Flow Simulations:Effect on Pulse Waves and Parameter Estimation

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Communications in Computational Physics 2008年第7期4卷 317-336页

作者： j.Alastruey K.H.parker j.Peiro S.j.Sherwin Department of Aeronautics Imperial College LondonSouth Kensington CampusLondon SW72AZU.K Department of Bioengineering Imperial College LondonSouth Kensington CampusLondon SW72AZU.K.

Several lumped parameter,or zero-dimensional(0-D),models of the microcirculation are coupled in the time domain to the nonlinear,one-dimensional(1-D)equations of blood flow in large arteries.A linear analysis of the coupled system,together with in vivo observations,shows that:(i)an inflow resistance that matches the characteristic impedance of the terminal arteries is required to avoid non-physiological wave reflections;(ii)periodic mean pressures and flow distributions in large arteries depend on arterial and peripheral resistances,but not on the compliances and inertias of the system,which only affect instantaneous pressure and flow waveforms;(iii)peripheral inertias have a minor effect on pulse waveforms under normal conditions;and(iv)the time constant of the diastolic pressure decay is the same in any 1-D model artery,if viscous dissipation can be neglected in these arteries,and it depends on all the peripheral compliances and resistances of the *** this analysis,we propose an algorithm to accurately estimate peripheral resistances and compliances from in vivo *** algorithm is verified against numerical data simulated using a 1-D model network of the 55 largest human arteries,in which the parameters of the peripheral windkessel outflow models are known a *** and flow waveforms in the aorta and the first generation of bifurcations are reproduced with relative root-mean-square errors smaller than 3%.

关键词： Pulse wave propagation one-dimensional modelling lumped parameter outflow models time-domain coupling arterial compliance peripheral compliance peripheral resistance multiscale modelling.

On the use of residual dipolar couplings in multi-state structure calculation of two-domain proteins

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Magnetic Resonance Letters 2022年第2期2卷 61-68,I0002页

作者： Alexandra Born Morkos A.Henen parker j.Nichols Beat Vogeli University of Colorado Anschutz Medical Campus Department of Biochemistry and Molecular Genetics12801 East 17th AvenueAuroraCO80045USA Faculty of Pharmacy Mansoura UniversityMansoura35516Egypt

Residual dipolar couplings(RDCs)are powerful nuclear magnetic resonance(NMR)probes for the structure calculation of ***,an alignment tensor that defines the orientation of the entire molecule relative to the magnetic field is determined either before refinement of individual bond vectors or simultaneously with this *** single-domain proteins this approach works well since all bond vectors can be described within the same coordinate frame,which is given by the alignment ***,novel approaches are sought after for systems where no universal alignment tensor can be ***,we present an approach that can be applied to two-domain proteins that enables the calculation of multiple states within each domain as well as with respect to the relative positions of the two domains.

关键词： RDC Residual dipolar coupling Two-domain protein Multi-state structure

Luminometric Studies of Yeast Response to Complex Environmental Calcium Variations Demonstrate Sensing of External Calcium Ion Changes

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Advances in Microbiology 2022年第9期12卷 555-567页

作者： Augustus C. parker david A. Mintz Francisco j. Solis Pamela A. Marshall School of Mathematical and Natural Sciences Arizona State University Glendale USA

The response of yeast to sharp environmental increases in calcium concentration has been extensively studied. However, systematic studies of the response under more general changes are still lacking. Only limited exploration of cellular responses has been conducted where calcium concentration is decreased. This article describes a set of luminometric experiments that monitor the cytosolic calcium concentration under changing external concentration conditions. As a decrease in external calcium concentrations requires the use of large sample volumes, the experiments require the use of equipment adapted for this purpose. We describe the modification of commercial luminometric equipment to make the exploration possible. We explore the yeast cellular behavior when an increase in external calcium concentration is followed by a decrease in external calcium concentration. We compare these results with those from the case of a double pulse of concentration increase. Results from the experiment show that the first, concentration increasing pulse produces the well-known sharp increase in cytosolic calcium followed by calcium sequestration to return to a cytosolic concentration near its initial condition. Surprisingly, the calcium decrease step shows similar results with a cytosolic increase followed by a return to lower levels. The results suggest the presence of a calcium sensing mechanism regulating calcium influx from external sources. This mechanism would produce channel opening as a response to any changes in external concentration, be it an enhancement or a depletion.

关键词： Saccharomyces cerevisiae Calcium Homeostasis Extracellular Ion Changes

The tumor suppressor RASSF1A is a novel effector of small G protein Rap1A

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Protein & Cell 2011年第3期2卷 237-249页

作者： Sunil K.Verma Trivadi S.Ganesan Uday Kishore Peter j.parker Department of Medical Oncology Medical Sciences DivisionThe University of OxfordOxford OX39DUUK Ovarian Cancer Group CRUK Molecular Oncology LaboratoriesWeatherall Institute of Molecular MedicineJohn Radcliffe HospitalHeadingtonOxford OX39DSUK Protein Phosphorylation Laboratory London Research InstituteCRUK Lincoln's Inn Fields Laboratories44 Lincoln's Inn FieldsLondon WC2A 3PXUK Kings College London The Division of Cancer StudiesSection of Cancer Cell Biology and Imaging2nd FloorNew Hunt's HouseGuy's HospitalSt Thomas StreetLondon SE11ULUK Current address:Center for Cellular and Molecular Biology Uppal RoadHyderabad 500007India Current address:Cancer Institute&Institute of Molecular Medicine Amrita Institute of Medical SciencesElamakkara P.O.KochiKerala 682026India Center for Infection Immunity and Disease MechanismsBiosciencesSchool of Health Sciences and Social CareBrunel UniversityUxbridge UB83PHWest LondonUK

Rap1A is a small G protein implicated in a spectrum of biological processes such as cell proliferation,adhesion,differentiation,and *** downstream effectors through which Rap1A mediates its diverse effects are largely *** we show that Rap1A,but not the related small G proteins Rap2 or Ras,binds the tumor suppressor Ras association domain family 1A(RASSF1A)in a manner that is regulated by phosphorylation of *** with Rap1A is shown to influence the effect of RASSF1A on microtubule behavior.

关键词： RASSF1A Rap1A microtubule vimentin protein-protein interaction

A review of potential biomarkers for assessing physical and psychological trauma in paediatric burns

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Burns & Trauma 2021年第1期9卷 652-677页

作者： Morgan Carlton j.anne Voisey Tony j.parker Chamindie Punyadeera Leila Cuttle Queensland University of Technology(QUT) Centre for Children’s Burn and Trauma ResearchCentre for Children’s Health ResearchSouth BrisbaneQueenslandAustralia Queensland University of Technology(QUT) Faculty of HealthSchool of Biomedical SciencesBrisbaneQueenslandAustralia Queensland University of Technology(QUT) Faculty of HealthSchool of Biomedical SciencesSaliva and Liquid Biopsy Translational LaboratoryBrisbaneQueenslandAustralia

Biological markers that evaluate physical healing as well as psychological impact of a burn are essential for effective treatment of paediatric *** obj.ctive of this review is to summarize the evidence supporting the use of biomarkers in children with *** extensive review of the literature was performed using PubMed.A total of 59 biomarkers were identified relating to burn presence,specifically relating to processes involved in inflammation,wound healing,growth and *** addition,biomarkers involved in the stress response cascade following a burn trauma were also *** many biomarkers have been identified that are potentially associated with burn-related physical and psychological trauma,an understanding of burn biology is still lacking in *** propose that future research in the field of children’s burns should be conducted using broad screening methods for identifying potential biomarkers,examine the biological interactions of different biomarkers,utilize child-appropriate biological fluids such as urine or saliva,and include a range of different severity *** further research,the biological response to burn inj.ry may be fully realized and clinically relevant diagnostic tests and treatment therapies utilizing these biomarkers could be developed,for the improvement of healing outcomes in paediatric burn patients.

关键词： Paediatric burns Biomarker Inflammatory Hypothalamic-pituitary-adrenal axis Physical trauma Psychological trauma

A review of dual-spin proj.ctile stability

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Defence Technology（防务技术） 2020年第1期16卷 1-9页

作者： j.mes Norris Amer Hameed j.hn Economou Simon parker Centre for Defence Engineering Cranfield UniversityDefence Academy of the United KingdomShrivenhamSN68LA United Kingdom BAE Systems United Kingdom

This paper gives a succinct review of dual-spinproj.ctile stability and some technologies relating to *** describes how the traditional stability factors from linear proj.ctile theory are modified to better describe a controlled dual-spin ***,it reviews works which have investigated how different aspects of a controlled dual-spin design can affect flight stability,primarily airframe structure and canard properties.A conclusion is given,highlighting important guidelines from the enclosed discussions.

关键词： Guided proj.ctiles Dual-spin Gyroscopic Dynamic Stability Canards

The role of adipose tissue in fatty liver diseases

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Liver Research 2018年第1期2卷 35-42页

作者： Richard parker Liver Unit St James's University HospitalLeedsUK

Fatty liver disease is almost always a consequence of obesity or alcohol *** both cases significant changes to adipose tissue(AT)occur,which are remarkably similar despite their different *** and hypoxic adipocytes develop an inflammatory phenotype and become necrotic,secreting inflammatory cytokines into circulation,principally but not limited to tumor necrosis factor(TNF)α.The secretion of adipokines is altered in obesity and alcohol *** acids,instead of being stored in adipocytes are delivered to the *** multiple pathways of adipose-liver crosstalk contribute to the development and progression of liver disease:TNFαinduces hepatocyte death and modulates hepatic immune *** acids promote hepatic steatosis and are pro-inflammatory,whilst adipokines mediate and exacerbate liver inj.ry,for example leptin enhances fibrotic responses to *** nonalcoholic fatty liver disease(NAFLD)reducing adipose inflammation through weight loss or thiazolidinediones(TZDs)both improve liver *** data that suggest that this might also be of benefit in alcoholic liver disease(ALD)but human studies are lacking at present.

关键词： Fatty liver disease Adipose tissue(AT) Leptin Adiponectin Tumor necrosis factor(TNF)α